Recent Italian reports indicate the presence of different phytoplasmas in medicinal herbs showing stunting, witches’ broom and yellowing: stolbur in Hyssopus officinalis (hyssop) and in Parietaria sp., aster yellows in Digitalis lanata (woolly foxglove) and Grindelia robusta (gumweed), and ash yellows in Hypericum perforatum (St. John's worth). Comparative biochemical analyses by GC-MS, reversed-phase HPLC and other methodologies of healthy and infected plants provide indication about metabolic modifications related to the presence of phytoplasmas. Hyssop oil samples showed content of isopinocamphone and pinocamphone correspondent to 44,7% and 29,1%, and to 6,2% and 3,92% respectively from healthy and infected plants, with a consequent reduction of antimicrobial action for the oil from infected hyssop. In the same oil it was also observed higher levels of bicyclogermacrene, germacrene D and caryophyllene oxide. Parietaria flavonoid quality and quantity reduction was observed: quercetin, canferol and isorhamnetin were detected only in healthy material, while from infected plants rutin (a quercetin glycoside) was detected but 83% less concentrated. Qualitative and quantitative analysis of cardiac glycosides from woolly foxglove demonstrated that the secondary metabolite mainly affected was lanatoside C with a 50% of reduction in infected plants. Among 42 components analysed in oil from infected gumweed, a higher percentage of selected monoterpenes was observed, concentration of limonene and borneol acetate was almost 50% higher, and that of borneol was about 30% higher. Infected St. John's worth plants showed a decreased amount of rutin (1,96 vs. 4,96 mg/g), hyperoside (2.38 vs 3.04 mg/g), isoquercitrin (1.47 vs. 3.50 mg/g), amentoflavone (0.12 vs. 0.39 mg/g), pseudohypericin (1.41 vs. 2.29 mg/g), whereas chlorogenic acid content was doubled (1.56 vs. 0.77 mg/g); essential oil revealed an increased abundance of sesquiterpenes (-caryophyllene, -elemene and germacrene D in particular) and a matching decrease in monoterpene hydrocarbons and aliphatics.
A.Bertaccini, N.Contaldo, S.Paltrinieri, M.G.Bellardi (2010). Modification of secondary metabolites production in medicinal herbs infected by phytoplasmas. SITGES : COST ACTION FA0807.
Modification of secondary metabolites production in medicinal herbs infected by phytoplasmas
BERTACCINI, ASSUNTA;CONTALDO, NICOLETTA;PALTRINIERI, SAMANTA;BELLARDI, MARIA GRAZIA
2010
Abstract
Recent Italian reports indicate the presence of different phytoplasmas in medicinal herbs showing stunting, witches’ broom and yellowing: stolbur in Hyssopus officinalis (hyssop) and in Parietaria sp., aster yellows in Digitalis lanata (woolly foxglove) and Grindelia robusta (gumweed), and ash yellows in Hypericum perforatum (St. John's worth). Comparative biochemical analyses by GC-MS, reversed-phase HPLC and other methodologies of healthy and infected plants provide indication about metabolic modifications related to the presence of phytoplasmas. Hyssop oil samples showed content of isopinocamphone and pinocamphone correspondent to 44,7% and 29,1%, and to 6,2% and 3,92% respectively from healthy and infected plants, with a consequent reduction of antimicrobial action for the oil from infected hyssop. In the same oil it was also observed higher levels of bicyclogermacrene, germacrene D and caryophyllene oxide. Parietaria flavonoid quality and quantity reduction was observed: quercetin, canferol and isorhamnetin were detected only in healthy material, while from infected plants rutin (a quercetin glycoside) was detected but 83% less concentrated. Qualitative and quantitative analysis of cardiac glycosides from woolly foxglove demonstrated that the secondary metabolite mainly affected was lanatoside C with a 50% of reduction in infected plants. Among 42 components analysed in oil from infected gumweed, a higher percentage of selected monoterpenes was observed, concentration of limonene and borneol acetate was almost 50% higher, and that of borneol was about 30% higher. Infected St. John's worth plants showed a decreased amount of rutin (1,96 vs. 4,96 mg/g), hyperoside (2.38 vs 3.04 mg/g), isoquercitrin (1.47 vs. 3.50 mg/g), amentoflavone (0.12 vs. 0.39 mg/g), pseudohypericin (1.41 vs. 2.29 mg/g), whereas chlorogenic acid content was doubled (1.56 vs. 0.77 mg/g); essential oil revealed an increased abundance of sesquiterpenes (-caryophyllene, -elemene and germacrene D in particular) and a matching decrease in monoterpene hydrocarbons and aliphatics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
